Action for upright pianofortes.



No. 894,612. PATENTED JULY 28, 1908.

J. DBLERUE.

ACTION FOR UPRIGHT PIANOPORTES.

APPLICATION FILED MAY4, 1907.

UNITED STATES PATENT omen.

JOSEPH DELERUE, OF OPOR'IO, PORTUGAL.

ACTION FOR UPRIGHT PIANOFORTES.

To all whom it may concern:

Be it known that I, JosEPH DELERUE, of 10 Campo da Regeneracao,Oporto,-Portugal, piano manufacturer, have invented an Action forUpright Pianofortes, of which the following is a full, clear, and exactdescription.

The invention relates to an action for piano fortes and is especiallyadapted for upright pianos and consists in certain novel constructionand combination of parts here inafter described and claimed.

This action is provided in a well-known manner with a check arrangedunder the hammer-butt.

The invention consists essentially in arranging at the upper part of thejack a lateral arm and in mounting the check on a U- shaped springsecured near the axis of the whip and passing through an opening of theac r.

In the accompanying drawing: Figure 1 is an elevation of the action.Fig. 2 is a front View of the jack.

As shown in this drawing, the device cornprises a hammer a mounted on ahammerutt b pivoted at 6 This hammer-butt is provided with a notch c inwhich the upper part of the jack engages. is arranged on the hammer-buttb opposite the hammer and in an inclined position with reference to theprolongation of the latter.

The form and proportions of the hammer butt determine in a great measurethe properties of the iano-action. A large distance is preferably ieftbetween the articulation and the point of the nose 6; for an action ofthis kind, the distance is of at least 27 millimeters.

The jack f is pivoted at its lower end at f upon the whip g pivoted inits turn to a fork h secured to the support *6 or to a bar sustainingthe parts. This arrangement of the jack has for effect to decrease thespace which is required for locating the parts placed in its opening, ashereinafter described. The up per part of the ack is constituted by anangular arm j, adapted to engage the notch of the hammer-butt b.

The jack is provided near its articulation f 1 with a lug f againstwhich bears a spiral spring k carried by the whip g. This spring is isadapted to maintain the free end of the jack in the notch of thehammer-butt.

The jack is provided toward the lower half of its length with an openingor window 1 to allow the passage of the check m and of its Specificationof Letters Patent.

Application filed May 4, 1907.

A countercheck cZ Patented July 28, 1908.

Serial No. 371,774.

spring n, as hereinafter described. Above this opening is secured a rod0 carrying a small piece of thin wood p. This projection bears against apivoted adjusting screw 9, which ermits of controlling the exact pointat whic the jack leaves the hammer. 'It is to be observed that this partis placed very near to the free end of the jack and very far from thearticulation of the latter, thereby allowing an adequate adjustment ofthe operation of the jack.

The hammer check m consists of a very small piece of wood, lined at itsupper part and secured to a substantially U-shaped spring n made of wireand passing twice through the opening Z of the jack the bent portion ofthe spring being in front of the jack. It is secured on the Whip g atabout the articulation of the same. The wire is flattened under thesmall wood plate.

- The operation of this device is as follows The movement of the keyimparts to the jack an upward motion until it is stopped by the meetingof the arm p with the adjusting screw The hammer is set in motion by thejac k during its upward motion and is left by the latter but at a verysmall distance from the strings, and this at the moment when it isstopped by the adjusting abutment. Exactly at this moment, the checkwhich has been lifted with the jack comes into contact with thecountercheck which has been moved from left to right. In this positionofthe two parts, if the action of the ey is moderate, a small downwardmotion of the check takes place in virtue of the flexure of the springabout the middle of the curve of the spring n. This first movement ofthe check preceding but very little the moment at which the strike ofthe hammer takes place, has for consequence to impart to the same asmall backward motion accelerating the recoil of the hammer at thepercussion. This operation takes place when the key has come to itslowermost position. In this position, the striking operation is completeand the hammer is really maintained by the check the spring of which isbent. If the operation of the key has been very energetic, thecountercheck will then bear fully against the check and will cause thetwo arms of the spring to yield almost simultaneously.

.The rapid repetition of the note is facilitated by the yield of thespring of the check, which causes the hammer to move back up- Ward andalloWs the jack to easily enter beneath the nose of the hammer-butt.

The above arrangements have been given by Way of example only; theforms, dimensions and detail arrangements may vary in all cases Withoutdeparting from the pr1nciple of the invention.

Claim:

1. In a piano action, the combination With the hammer butt, of acounter-check fixed to the hammer butt, and beneath and check and asubstantially U-shaped spring carrying the check, the bent portion ofthe spring being in front of the jack.

spring passing through the opening and hav- 3 1 ing its bent portion infront of the jack, said spring being provided with a check for thepurpose set forth.

The foregoing specification of my action for upright pianofortes signedby me this i tWelft in front of the axis of said hammer butt, a

1 day of April 1907.

JOSEPH DELERUE. Witnesses SIMZo EsMERI'I.

ALVARO DO NASGIMENTE FERREIRA

